Maternal and neonatal outcomes following waterbirth: a cohort study of 17 530 waterbirths and 17 530 propensity score-matched land births

OBJECTIVE

Investigate maternal and neonatal outcomes following waterbirth.

DESIGN

Retrospective cohort study, with propensity score matching to address confounding.

SETTING

Community births, United States.

SAMPLE

Medical records-based registry data from low-risk births were used to create waterbirth and land birth groups (n = 17 530 each), propensity score-matched on >80 demographic and pregnancy risk covariables.

METHODS

Logistic regression models compared outcomes between the matched waterbirth and land birth groups.

MAIN OUTCOME MEASURES

Maternal: immediate postpartum transfer to a hospital, any genital tract trauma, severe (3rd/4th degree) trauma, haemorrhage >1000 mL, diagnosed haemorrhage regardless of estimated blood loss, uterine infection, uterine infection requiring hospitalisation, any hospitalisation in the first 6 weeks. Neonatal: umbilical cord avulsion; immediate neonatal transfer to a hospital; respiratory distress syndrome; any hospitalisation, neonatal intensive care unit (NICU) admission, or neonatal infection in the first 6 weeks; and neonatal death.

RESULTS

Waterbirth was associated with improved or no difference in outcomes for most measures, including neonatal death (adjusted odds ratio [aOR] 0.56, 95% CI 0.31-1.0), and maternal or neonatal hospitalisation in the first 6 weeks (aOR 0.87, 95% CI 0.81-0.92 and aOR 0.95, 95% CI 0.90-0.99, respectively). Increased morbidity in the waterbirth group was observed for two outcomes only: uterine infection (aOR 1.25, 95% CI 1.05-1.48) (but not hospitalisation for infection) and umbilical cord avulsion (aOR 1.57, 95% CI 1.37-1.82). Our results are concordant with other studies: waterbirth is neither as harmful as some current guidelines suggest, nor as benign as some proponents claim.

TWEETABLE ABSTRACT

New study demonstrates #waterbirth is neither as harmful as some current guidelines suggest, nor as benign as some proponents claim. @TheUpliftLab @BovbjergMarit @31415926abc @NICHD_NIH.

Impact of maternal obesity on fetal cardiac screening: which follow-up strategy is cost-effective?

OBJECTIVE

To perform a cost-effectiveness analysis of different follow-up strategies for non-obese and obese women who had incomplete fetal cardiac screening for major congenital heart disease (CHD).

METHODS

Three decision-analytic models, one each for non-obese, obese and Class-III-obese women, were developed to compare five follow-up strategies for initial suboptimal fetal cardiac screening. The five strategies were: (1) no follow-up ultrasound (US) examination but direct referral to fetal echocardiography (FE); (2) one follow-up US, then FE if fetal cardiac views were still suboptimal; (3) up to two follow-up US, then FE if fetal cardiac views were still suboptimal; (4) one follow-up US and no FE; and (5) up to two follow-up US and no FE. The models were designed to identify fetuses with major CHD in a theoretical cohort of 4 000 000 births in the USA. Outcomes related to neonatal mortality and neurodevelopmental disability were evaluated. A cost-effectiveness willingness-to-pay threshold was set at US$100 000 per quality-adjusted life year (QALY). Base-case and sensitivity analysis and Monte-Carlo simulation were performed.

RESULTS

In our base-case models for all body mass index (BMI) groups, no follow-up US, but direct referral to FE led to the best outcomes, detecting 7%, 25% and 82% more fetuses with CHD in non-obese, obese and Class-III-obese women, respectively, compared with the baseline strategy of one follow-up US and no FE. However, no follow-up US, but direct referral to FE was above the US$100 000/QALY threshold and therefore not cost-effective. The cost-effective strategy for all BMI groups was one follow-up US and no FE. Both up to two follow-up US with no FE and up to two follow-up US with FE were dominated (being more costly and less effective), while one follow-up US with FE was over the cost-effectiveness threshold. One follow-up US and no FE was the optimal strategy in 97%, 93% and 86% of trials in Monte-Carlo simulation for non-obese, obese and Class-III-obese models, respectively.

CONCLUSION

For both non-obese and obese women with incomplete fetal cardiac screening, the optimal CHD follow-up screening strategy is no further US and immediate referral to FE; however, this strategy is not cost-effective. Considering costs, one follow-up US and no FE is the preferred strategy. For both obese and non-obese women, Monte-Carlo simulations showed clearly that one follow-up US and no FE was the optimal strategy. Both non-obese and obese women with initial incomplete cardiac screening examination should therefore be offered one follow-up US. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Detection of fetal cardiac anomalies: cost-effectiveness of increased number of cardiac views

OBJECTIVE

To compare the recommended three-view fetal heart screening method to detect major congenital heart disease (CHD) with more elaborate screening strategies to determine the cost-effective strategy in unselected (low-risk) pregnancies.

METHODS

A decision-analytic model was designed to compare four screening strategies to identify fetuses with major CHD in a theoretical cohort of 4 000 000 births in the USA. The four strategies were: (1) three views: four-chamber view (4CV) and views of the left (LVOT) and right (RVOT) ventricular outflow tracts; (2) five views: 4CV, LVOT, RVOT and longitudinal views of the ductal arch and aortic arch; (3) five axial views: 4CV, LVOT, RVOT, three-vessel (3V) view and three-vessels-and-trachea view; and (4) six views: 4CV, LVOT, RVOT and 3V views and longitudinal views of the ductal arch and aortic arch. Outcomes related to neonatal mortality and neurodevelopmental disability were evaluated. The analysis was performed from a healthcare-system perspective, with a cost-effectiveness willingness-to-pay threshold set at $100 000 per quality-adjusted life year (QALY). Baseline analysis, one-way sensitivity analysis and Monte-Carlo simulation were performed.

RESULTS

In our baseline model, screening with five axial views was the optimal strategy, detecting 3520 more CHDs, and resulting in 259 fewer children with neurodevelopmental disability, 40 fewer neonatal deaths and only slightly higher costs, compared with screening with the currently recommended three views. Screening with six views was more effective, but also cost considerably more, compared with screening with five axial views, and had an incremental cost of $490 023/QALY, which was over the willingness-to-pay threshold. The five-view strategy was dominated by the other three strategies, i.e. it was more costly and less effective in comparison. The data were robust when tested with Monte-Carlo and one-way sensitivity analysis.

CONCLUSION

Although current guidelines recommend a minimum of three views for detecting CHD during the mid-trimester anatomy scan, screening with five axial views is a cost-effective strategy that may lead to improved outcome compared with three-view screening. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Second-trimester abortion attitudes and practices among maternal-fetal medicine and family planning subspecialists

BACKGROUND

Patients deciding to undergo dilation and evacuation (D&E) or induction abortion for fetal anomalies or complications may be greatly influenced by the counseling they receive. We sought to compare maternal-fetal medicine (MFM) and family planning (FP) physicians' attitudes and practice patterns around second-trimester abortion for abnormal pregnancies.

METHODS

We surveyed members of the Society for Maternal-Fetal Medicine and Family Planning subspecialists in 2010-2011 regarding provider recommendations between D&E or induction termination for various case scenarios. We assessed provider beliefs about patient preferences and method safety regarding D&E or induction for various indications. We compared responses by specialty using descriptive statistics and conducted unadjusted and adjusted analyses of factors associated with recommending a D&E.

RESULTS

Seven hundred ninety-four (35%) physicians completed the survey (689 MFMs, 105 FPs). We found that FPs had 3.9 to 5.5 times higher odds of recommending D&E for all case scenarios (e.g. 80% of FPs and 41% of MFMs recommended D&E for trisomy 21). MFMs with exposure to family planning had greater odds of recommending D&E for all case scenarios (p < 0.01 for all). MFMs were less likely than FPs to believe that patients prefer D&E and less likely to feel that D&E was a safer method for different indications.

CONCLUSION

Recommendations for D&E or induction vary significantly depending on the type of physician providing the counseling. The decision to undergo D&E or induction is one of clinical equipoise, and physicians should provide unbiased counseling. Further work is needed to understand optimal approaches to shared decision making for this clinical decision.

Term elective induction of labour and perinatal outcomes in obese women: retrospective cohort study

OBJECTIVE

To compare perinatal outcomes between elective induction of labour (eIOL) and expectant management in obese women.

DESIGN

Retrospective cohort study.

SETTING

Deliveries in California in 2007.

POPULATION

Term, singleton, vertex, nonanomalous deliveries among obese women (n = 74 725).

METHODS

Women who underwent eIOL at 37 weeks were compared with women who were expectantly managed at that gestational age. Similar comparisons were made at 38, 39, and 40 weeks. Results were stratified by parity. Chi-square tests and multivariable logistic regression were used for statistical comparison.

MAIN OUTCOME MEASURES

Method of delivery, severe perineal lacerations, postpartum haemorrhage, chorioamnionitis, macrosomia, shoulder dystocia, brachial plexus injury, respiratory distress syndrome.

RESULTS

The odds of caesarean delivery were lower among nulliparous women with eIOL at 37 weeks [odds ratio (OR) 0.55, 95% confidence interval (CI) 0.34-0.90] and 39 weeks (OR 0.77, 95% CI 0.63-0.95) compared to expectant management. Among multiparous women with a prior vaginal delivery, eIOL at 37 (OR 0.39, 95% CI 0.24-0.64), 38 (OR 0.65, 95% CI 0.51-0.82), and 39 weeks (OR 0.67, 95% CI 0.56-0.81) was associated with lower odds of caesarean. Additionally, eIOL at 38, 39, and 40 weeks was associated with lower odds of macrosomia. There were no differences in the odds of operative vaginal delivery, lacerations, brachial plexus injury or respiratory distress syndrome.

CONCLUSIONS

In obese women, term eIOL may decrease the risk of caesarean delivery, particularly in multiparas, without increasing the risks of other adverse outcomes when compared with expectant management.

Effect of magnesium sulfate exposure on term neonates

OBJECTIVE

To compare neonatal intensive care unit and special care unit (NICU) admission rates between term neonates exposed to antenatal magnesium sulfate (MS) and those unexposed.

STUDY DESIGN

We performed a retrospective cohort study of all singleton neonates ≥37 weeks born to women with pre-eclampsia from August 2006 to July 2008. Cases were defined by antenatal exposure to MS and controls by absence of MS exposure. The primary outcome was NICU admission. Data were analyzed via univariable and multivariable regression analyses.

RESULT

In all, 28 (14.7%) out of 190 MS-exposed neonates ≥37 weeks were admitted to the NICU, compared with 4 (5.4%) of 74 non-exposed neonates (P=0.04). This association persisted after controlling for potential confounding variables including severe pre-eclampsia and cesarean delivery (AOR 3.69, 1.13 to 11.99). NICU admission was associated in a dose-dependent relationship with total hours and mean dose of MS exposure. Number needed to harm with MS was 11 per NICU admission. Among neonates admitted to the NICU, MS-exposed were more likely to require fluid and nutritional support than unexposed neonates (60.7 vs 0%, P=0.04), and trended toward more frequent requirement for respiratory support and greater length of stay.

CONCLUSION

In term neonates, MS exposure may be associated independently with NICU admission in a dose-dependent relationship. Requirements for fluid and nutritional support are common in this group, likely due to feeding difficulties in exposed neonates. Assessment of acute care needs among all neonates exposed to MS for maternal eclampsia prophylaxis should be considered.

Evaluating the competing risks of HIV acquisition and maternal mortality in Africa: a decision analysis

OBJECTIVE

To model the risk of HIV acquisition and maternal mortality for women in four African countries in the light of previous data on risk of HIV acquisition and hormonal contraceptive use.

DESIGN

Decision analysis.

SETTING

Chad, Kenya, South Africa and Uganda.

POPULATION

Women of reproductive age, at risk of HIV, who do not desire pregnancy.

METHODS

A decision analysis model was built to compare the consequences of removing progestin injectables from use, assuming an increased risk of HIV acquisition. Three scenarios were considered in four African countries: replacement of progestin injectables with no method, with combined oral contraceptives (COC) or with an intrauterine device (IUD). Health outcomes measured include: life-years, maternal mortality, HIV acquisition and unsafe abortion. Sensitivity analysis, including Monte Carlo simulation, was performed around all variables.

MAIN OUTCOME MEASURES

HIV acquisition, maternal mortality and life-years.

RESULTS

If progestin injectables are removed from use, without a minimum of 70-100% of women switching to an IUD or COCs, up to nine additional maternal deaths will occur for every case of HIV averted. Sensitivity analysis demonstrated that this finding persisted across a broad range of variables.

CONCLUSIONS

Contraception is critical to preserving life for women in Africa. In the absence of clear evidence regarding hormonal contraception and HIV acquisition, policy decisions must not overlook the very real risk of maternal mortality.

Impending macrosomia: will induction of labour modify the risk of caesarean delivery?

OBJECTIVE

To compare the annual incidence rates of caesarean delivery between induction of labour and expectant management in the setting of macrosomia.

DESIGN

This is a retrospective cohort study.

SETTING

Deliveries in the USA in 2003.

POPULATION

Singleton births of macrosomic neonates to low-risk nulliparous women at 39 weeks of gestation and beyond.

METHODS

Women who had induction of labour at 39 weeks of gestation with a neonatal birthweight of 4000 ± 125 g (3875-4125 g) were compared with women who delivered (either induced or spontaneous labour) at 40, 41 or 42 weeks (i.e. expectant management), assuming an intrauterine fetal weight gain of 200 g per additional week of gestation. Similar comparisons were made at 40 and 41 weeks of gestation. Chi-square test and multivariable logistic regression analysis were used for statistical comparison.

MAIN OUTCOME MEASURES

Method of delivery, 5-minute Apgar scores, neonatal injury.

RESULTS

There were 132,112 women meeting the study criteria. In women whose labours were induced at 39 weeks and who delivered a neonate with a birthweight of 4000 ± 125 g, the frequency of caesarean was lower compared with women who delivered at a later gestational age (35.2% versus 40.9%; adjusted OR 1.25, 95% CI 1.17-1.33). This trend was maintained at both 40 weeks (36.1% versus 42.6%; adjusted OR 1.31, 95% CI 1.23-1.40) and 41 weeks (38.9% versus 41.8%; adjusted OR 1.16, 95% CI 1.06-1.28) of gestation.

CONCLUSIONS

In the setting of known birthweight, it appears that induction of labour may reduce the risk of caesarean delivery. Future research should concentrate on clinical and radiological methods to better estimate birthweight to facilitate improved clinical care. These findings deserve examination in a large, prospective, randomised trial.

Perinatal morbidity associated with late preterm deliveries compared with deliveries between 37 and 40 weeks of gestation

OBJECTIVE

To estimate the risk of short-term complications in neonates born between 34 and 36 weeks of gestation.

DESIGN

This is a retrospective cohort study.

SETTING

Deliveries in 2005 in the USA.

POPULATION

Singleton live births between 34 and 40 weeks of gestation.

METHODS

Gestational age was subgrouped into 34, 35, 36 and 37-40 completed weeks of gestation. Statistical comparisons were performed using chi-square test and multivariable logistic regression models, with 37-40 weeks of gestation designated as referent.

MAIN OUTCOME MEASURES

Perinatal morbidities, including 5-minute Apgar scores, hyaline membrane disease, neonatal sepsis/antibiotics use, and admission to the intensive care unit.

RESULTS

In all, 175,112 neonates were born between 34 and 36 weeks in 2005. Compared with neonates born between 37 and 40 weeks, neonates born at 34 weeks had higher odds of 5-minute Apgar <7 (adjusted odds ratio [aOR] 5.51, 95% CI 5.16-5.88), hyaline membrane disease (aOR 10.2, 95% CI 9.44-10.9), mechanical ventilation use >6 hours (aOR 9.78, 95% CI 8.99-10.6) and antibiotic use (aOR 9.00, 95% CI 8.43-9.60). Neonates born at 35 weeks were similarly at risk of morbidity, with higher odds of 5-minute Apgar <7 (aOR 3.42, 95% CI 3.23-3.63), surfactant use (aOR 3.74, 95% CI 3.21-4.22), ventilation use >6 hours (aOR 5.53, 95% CI 5.11-5.99) and neonatal intensive-care unit admission (aOR 11.3, 95% CI 11.0-11.7). Neonates born at 36 weeks remain at higher risk of morbidity compared with deliveries at 37-40 weeks of gestation.

CONCLUSIONS

Although the risk of undesirable neonatal outcomes decreases with increasing gestational age, the risk of neonatal complications in late preterm births remains higher compared with infants delivered at 37-40 weeks of gestation.

Diagnosis and morbidity of placenta accreta

OBJECTIVE

To examine the diagnostic precision of ultrasound examination for placenta accreta in women with placenta previa and to compare the morbidity associated with accreta to that of previa alone.

METHODS

This was a retrospective cohort study of all women with previa with/without accreta examined at the University of California, San Francisco (UCSF) between 2002 and 2008. The sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of ultrasound examination for the diagnosis of accreta were calculated and compared with results from similar studies in the literature. Univariable analysis was used to compare clinical outcomes.

RESULTS

The PPV of an ultrasound diagnosis of accreta was 68% and NPV was 98%. Ultrasound had a sensitivity of 89.5%. Compared with previa alone, accreta had an odds ratio (OR) of 89.6 (95% CI, 19.44-412.95) for estimated blood loss > 2 L, an OR of 29.6 (95% CI, 8.20-107.00) for transfusion and an OR of 8.52 (95% CI, 2.58-28.11) for length of hospital stay > 4 days.

CONCLUSION

Placenta accreta is associated with greater morbidity than is placenta previa alone. Ultrasound examination is a good diagnostic test for accreta in women with placenta previa. This is consistent with most other studies in the literature.

Single- versus double-layer hysterotomy closure at primary caesarean delivery and bladder adhesions

OBJECTIVE

To determine the association between single-layer (one running suture) and double-layer (second layer or imbricating suture) hysterotomy closure at primary caesarean delivery and subsequent adhesion formation.

DESIGN

A secondary analysis from a prospective cohort study of women undergoing first repeat caesarean section.

SETTING

Department of Obstetrics and Gynecology, Stanford University, Stanford, CA, USA.

POPULATION

One hundred and twenty-seven pregnant women undergoing first repeat caesarean section.

METHODS

Patient records were reviewed to identify whether primary caesarean hysterotomies were closed with a single or double layer. Data were analysed by Fisher's exact tests and multivariable logistic regression.

MAIN OUTCOME MEASURE

Prevalence rate of pelvic and abdominal adhesions.

RESULTS

Of the 127 women, primary hysterotomy closure was single layer in 56 and double layer in 71. Single-layer hysterotomy closure was associated with bladder adhesions at the time of repeat caesarean (24% versus 7%, P = 0.01). Single-layer closure was associated in this study with a seven-fold increase in the odds of developing bladder adhesions (odds ratio, 6.96; 95% confidence interval, 1.72-28.1), regardless of other surgical techniques, previous labour, infection and age over 35 years. There was no association between single-layer closure and other pelvic or abdominal adhesions.

CONCLUSIONS

Primary single-layer hysterotomy closure may be associated with more frequent bladder adhesions during repeat caesarean deliveries. The severity and clinical implications of these adhesions should be assessed in large prospective trials.

Gestational diabetes: diagnosis and management

PURPOSE

To review the diagnosis and management of gestational diabetes.

EPIDEMIOLOGY

In the United States, approximately 2 to 5% of all pregnant women have gestational diabetes. Those women with a family history of type 2 diabetes mellitus, Asian or native American race, Latina ethnicity or obesity are at higher risk for developing gestational diabetes.

CONCLUSION

Women with gestational diabetes who are treated appropriately can achieve good outcomes in the majority of pregnancies. Frequent blood glucose monitoring, nutrition counseling and frequent physician contact allow for individualized care to achieve optimal outcomes. Such treatment includes diet, exercise and insulin. The use of oral hypoglycemic agents is controversial and there is some concern about worse maternal and neonatal outcomes as compared to treatment with insulin. Evolving technologies promise to provide more therapeutic options.

Chilean women's preferences regarding mode of delivery: which do they prefer and why?

OBJECTIVE

Caesarean section rates in Chile are reported to be as high as 60% in some populations. The purpose of this study was to determine pregnant Chilean women's preferences towards mode of delivery.

DESIGN

Interviewer-administered cross-sectional survey.

SETTING

Prenatal clinics in Santiago, Chile. Population Pregnant women in Santiago, Chile.

METHODS

Of 180 women completing the questionnaire, 90 were interviewed at a private clinic (caesarean delivery rate 60%) and 90 were interviewed at a public clinic (cesarean delivery rate 22%). Data collected included demographics, preferred mode of delivery, and women's attitudes towards vaginal and caesarean deliveries.

MAIN OUTCOME MEASURES

Mode of delivery preferences, perceptions of mode of delivery measured on a 1-7 Likert scale.

RESULTS

The majority of women (77.8%) preferred vaginal delivery, 9.4% preferred caesarean section, and 12.8% had no preference. There was no statistical difference in preference between the public clinic (11% preferred caesarean) and the private clinic (8% preferred caesarean, P= 0.74). Overall, women preferring caesarean birth were slightly older than other groups (31.6 years, versus 28.4 years for women who preferred vaginal and 27.3 years for women who had no preference, P= 0.05), but there were otherwise no differences in parity, income, or education. On a scale of 1-7, women preferring caesarean birth rated vaginal birth as more painful, while women preferring vaginal birth rated it as less painful (5.8 versus 3.7, P= 0.003). Whether vaginal or caesarean, each group felt that their preferred mode of delivery was safer for their baby (P < 0.001).

CONCLUSIONS

Chilean women do not prefer caesarean section to vaginal delivery, even in a practice setting where caesarean delivery is more prevalent. Thus, women's preferences is unlikely to be the most significant factor driving the high caesarean rates in Chile.

Maternal complications of pregnancy increase beyond 40 weeks of gestation in low-risk women

OBJECTIVE

We sought to determine when rates of maternal pregnancy complications increase for low-risk nulliparous and multiparous women at term.

METHODS

We designed a retrospective cohort study of low-risk women delivered beyond 37 weeks gestational age from 1976 to 2001. Rates of mode of delivery and maternal complications of labor and delivery were examined by gestational age with both bivariate and multivariate analyses. Statistical significance was designated by P<0.05.

RESULTS

We found that among the 32,828 low-risk women who delivered at 37 completed weeks and beyond, the rates of primary cesarean delivery, operative vaginal delivery, third- or fourth-degree perineal lacerations, and chorioamnionitis all increased at 40 weeks of gestation (P<0.001), and the rate of postpartum hemorrhage increased at 41 weeks of gestation (P<0.001). These increases of rates of complications were larger and increased at an earlier gestational age among nulliparous women.

CONCLUSION

We found that the risk of maternal complications for otherwise low risk nulliparous and multiparous women increased as pregnancy progressed beyond 40 weeks of gestation. Counseling of women who progress past their EDC should include comparing the risks of induction of labor to that of expectant management.

Role of patient education level in predicting macrosomia among women with gestational diabetes mellitus

OBJECTIVE

To evaluate the role of education level in predicting the risk of macrosomia among women with gestational diabetes mellitus.

STUDY DESIGN

Women with gestational diabetes, who were referred to the California Diabetes and Pregnancy Sweet Success Program between June 2001 and December 2002, were included in the study. Multiple logistic regression was used estimate the risk of macrosomia, defined as a birth weight >4000 g.

RESULTS

Compared to college-educated women, high school- and middle school-educated women were 21% (relative risk (RR), 1.21; 95% confidence intervals (CI), 1.01-1.44) and 35% (RR, 1.35; 95% CI, 1.09-1.70) more likely to deliver a macrosomic infant, respectively.

CONCLUSION

Gestational diabetics with a lower level of educational attainment appear to have an increased risk of macrosomia. Future studies are necessary to determine whether this finding reflects a variation in adherence to recommended treatments by education/literacy level, or if it is a surrogate marker for intrinsic, biological differences or differences in lifestyle.

Ethnic variation in the prevalence of echogenic intracardiac foci and the association with Down syndrome

OBJECTIVE

To determine whether the prevalence of fetal echogenic intracardiac foci (EIF) differs according to maternal ethnicity.

METHODS

We performed a retrospective cohort study of all women undergoing second-trimester diagnostic ultrasound examination and amniocentesis at a prenatal diagnosis referral center from January 1 2000 to July 1 2003. Data were collected on the presence of EIF, gestational age at time of ultrasound scan, karyotype results, maternal age and ethnicity. Univariate and multivariate analyses of EIF, ethnicity and presence of aneuploidy were conducted.

RESULTS

Among the 7480 women qualifying for the study, EIF were found in 309 (4.1%). When maternal ethnicity was subdivided into Caucasian, African-American, Hispanic, Asian-American, Native American, Asian Indian, and Middle Eastern, the highest rates of EIF were found in fetuses of African-American (6.7%), Asian-American (6.9%), and Middle Eastern (8.1%) mothers compared to a rate of 3.3% in Caucasians (P < 0.001). In all ethnic groups except Hispanics, EIF was associated with an increased risk for Down syndrome (odds ratio range from 1.8 to 15.7).

CONCLUSIONS

African-American, Asian-American, and Middle Eastern patients are more likely than patients of other ethnicities to have a fetus with an EIF. Even controlling for ethnicity, fetuses with an EIF still have an increased risk for Down syndrome. As more data accumulate, the prevalence of EIF and its association with Down syndrome among different ethnic groups can be incorporated into patient counseling.

Risk factors and obstetric complications associated with macrosomia

OBJECTIVE

Macrosomia is associated with adverse maternal outcomes. The objective of this study was to characterize the epidemiology of macrosomia and related maternal complications.

METHOD

Live births (146,526) were identified between 1995 and 1999 in the Kaiser Permanente Medical Care Program's Northern California Region (KPMCP NCR) database. Bivariate and multivariate analyses were performed for risk factors and complications associated with macrosomia (birth weight >4500 g).

RESULT

Male infant sex, multiparity, maternal age 30-40, white race, diabetes, and gestational age >41 weeks were associated with macrosomia (p<0.001). In bivariate and multivariate analyses, macrosomia was associated with higher rates of cesarean birth, chorioamnionitis, shoulder dystocia, fourth-degree perineal lacerations, postpartum hemorrhage, and prolonged hospital stay (p<0.01).

CONCLUSION

Macrosomia was associated with adverse maternal outcomes in this cohort. More research is needed to determine how to prevent complications related to excessive birth weight.

The impact of the use of the isolated echogenic intracardiac focus as a screen for Down syndrome in women under the age of 35 years

OBJECTIVE

The purpose of this study was to determine the public health impact of the routine offering of amniocentesis to women under the age of 35 years who have an isolated fetal echogenic intracardiac focus on second trimester ultrasound scan.

STUDY DESIGN

A decision analytic model was designed that compared the accepted standard of second trimester triple marker screen for Down syndrome to a policy in which amniocentesis with an isolated echogenic intracardiac focus on ultrasound in addition to the triple marker screen is offered to all women in the United States who are <35 years of age. A sensitivity of 20%, an echogenic intracardiac focus screen positive rate of 5%, and a risk of Down syndrome of 1:1000 were assumed. A sensitivity analysis was performed that varied the screen positive rate, the sensitivity of echogenic intracardiac focus for Down syndrome, and the prescreen risk for Down syndrome in the population.

RESULTS

With the baseline sensitivities, rates, and risks, the use of isolated echogenic intracardiac focus as a screen would result in an additional 118,146 amniocenteses performed annually to diagnose 244 fetuses with Down syndrome. These amniocenteses would result in 582 additional miscarriages. It would be necessary to perform 485 amniocenteses that would result in 2.4 procedure-related losses for each additional Down syndrome fetus that was identified.

CONCLUSION

Although the echogenic intracardiac focus appears to be associated with a small increased risk of Down syndrome, its use as a screening tool in low-risk populations would lead to a large number of amniocenteses and miscarriages to identify a small number of Down syndrome fetuses.

Tocolysis with beta-adrenergic receptor agonists

Beta-adrenergic receptor agonists have been used for tocolysis in the setting of preterm labor for more than three decades. One of these agents, ritodrine hydrochloride, is the only Federal Drug Administration (FDA) approved drug for the treatment of preterm labor. Despite their widespread use, only a few prospective randomized placebo-controlled trials have been performed. These agents have been shown to have more patients deliver beyond 48 hours after the onset of treatment as compared with controls, but have never shown a difference in neonatal outcomes. Because they are one of the few tocolytic agents to have been shown to make a difference when compared with controls, the beta-agonists are commonly used as the control groups in studies examining the efficacy of newer tocolytic agents. In general, agents such as nifedipine, magnesium sulfate, and atosiban have not been shown to be more efficacious than the beta-agonists. However, several studies have shown these agents to have less side effects and lower discontinuation rates than the beta-agonists.

Measuring cost-effectiveness of surgical procedures

Our review of CEA of surgical procedures suggests that much of the existing cost analysis literature does not adhere to basic recommended analytic guidelines. However, those authors who specifically planned to perform a CEA analysis met all or nearly all of the methodologic principles (Table 1). Investigators who conduct CEA are strongly encouraged to use the many outstanding methodologic reviews for CEA. An example of threshold analysis was presented by Gray et al in their CEA of laparoscopy versus laparotomy for the treatment of ectopic pregnancy. They calculated that cost per successful treatment would be equal between the two strategies at an initial failure rate of 32% for laparoscopy (compared with their baseline value of 19%). This type of analysis is helpful, in addition to sensitivity analyses, to identify the value of a variable that results in an equal outcome. In the only cost-utility analysis performed on gynecologic surgery, Sculpher studied the trade-offs between a less invasive, less costly procedure (transcervical resection of the endometrium) with a more invasive, more costly, and more effective procedure (abdominal hysterectomy) to treat menorrhagia. Hysterectomy resulted in an incremental cost of 1,500 British pounds per QALY during 2 years of follow-up. This is much less than the range of $30,000 to $100,000 that represents a currently acceptable C/E ratio. Grover et al evaluated the cost-effectiveness of performing a concurrent hysterectomy in women undergoing bilateral salpingo-oophorectomy. They observed that in 45-year-old women, the additional concurrent procedure dominated the alternative strategy of bilateral salpingo-oophorectomy, being both less expensive and increasing average life expectancy. The concurrent hysterectomy strategy also dominated for women aged 55, but both with less cost-savings and gains in life expectancy compared with 45-year-old women. Selecting an appropriate time frame for the analysis is difficult and may dramatically affect the results of the analysis. The time frame should be long enough to measure all clinically relevant costs and benefits. For example, Kung et al compared the cost per cure of stress urinary incontinence of laparoscopic and open Burch procedures. The probability of cure after each procedure was estimated from a retrospective cohort of 62 women with a mean follow-up of 1.2 years for the laparoscopic Burch strategy and 2.7 years in the open Burch strategy. The authors found that the laparoscopic Burch dominated, with lower costs and a higher cure rate. However, the analysis would be more informative with much longer follow-up, because most women who undergo an incontinence procedure have a life expectancy far greater than 1 to 2 years. Ramsey et al performed an economic analysis to assess the long-term costs of behavioral therapy, pharmacotherapy, and surgical therapy used for stress urinary incontinence. They found that in the short-term, behavioral and pharmacotherapy were less costly. However, if life expectancy was equal to or greater than 3.5 years, surgical therapy was least costly. In many articles that evaluate the cost of managing ectopic pregnancy, only short-term costs of the procedures and follow-up visits are considered. Mol et al considered a longer time frame and also included the costs of infertility management based on the future probability of conception correlated with the different management strategies. Selection of an effectiveness measure after surgical intervention is often difficult and controversial. For benign disease, life years or QALYs will be minimally affected by a reasonably safe intervention. In the short-term, utility may be negatively affected by surgery and recovery. In longer-term analyses, these effects will be diluted by time and be negligible. Intermediate measures such as days of hospitalization averted or lives saved are often more appropriate for gynecologic interventions than are longer-term outcomes such as lif

Labor after previous cesarean: influence of prior indication and parity

OBJECTIVE

To determine whether the risk of cesarean for women who had trials of labor after one prior cesarean differs from that of nulliparas overall and by indications for those cesareans.

METHODS

We reviewed medical records of women who had trials of labor after cesareans between July 1984 and June 1996, and of nulliparas who delivered between December 1994 and August 1995. Cesarean rates for women with prior cesareans were compared with the rates for nulliparas overall and by prior cesarean indication (breech, failure to progress, nonreassuring fetal testing, or other). Lengths of labor for women who had repeat cesareans for failure to progress in index pregnancies were compared by prior cesarean indication.

RESULTS

The cesarean rate was 28.7% (634 of 2207) for the prior cesarean group and 13.5% (219 of 1617) for nulliparas (P =.001), and varied according to the prior cesarean indication (13.9%, 37.3%, 25. 4%, and 24.8% for breech, failure to progress, nonreassuring fetal testing, and other, respectively). Mean durations of labor in the index pregnancies for women who had cesareans for failure to progress were 13.9, 11.5, 13.4, and 15.1 hours for breech, failure to progress, nonreassuring fetal testing, and other, respectively.

CONCLUSION

Overall rates of cesareans were higher for women with one prior cesarean than for nulliparas. Rates of cesareans after trials of labor were related to the prior cesarean indications. Rates were highest for women whose prior cesareans were for failure to progress and lowest for women whose prior cesareans were for breech. The latter group had a rate that was essentially identical to that of nulliparas. Among women with cesareans for failure to progress in index pregnancies, lengths of labor were shorter for those whose prior cesareans were for failure to progress than for those whose prior cesareans were for other indications, suggesting that physicians may intervene earlier in these cases.

Intrapartum uterine rupture and dehiscence in patients with prior lower uterine segment vertical and transverse incisions

OBJECTIVE

To determine whether gravidas with prior low vertical uterine incision(s) are at a higher risk for uterine rupture during a trial of labor after cesarean delivery than women with prior low transverse uterine incision(s).

METHODS

The medical records of women undergoing a trial of labor after prior cesarean delivery over a 12-year period (July 1984-June 1996) at a tertiary-care hospital were reviewed. Maternal and perinatal outcomes for women with prior low transverse and low vertical incision were compared. Women whose low vertical incision was noted to extend into the corpus of the uterus were excluded. All uterine scar disruptions, which included both symptomatic ruptures and detected asymptomatic dehiscences, were analyzed together, and ruptures were examined separately.

RESULTS

The outcomes of 2912 patients undergoing trial of labor for the low transverse group and 377 patients undergoing trial of labor for the low vertical group were compared. Overall, there were 38 (1.3%) scar disruptions in the low transverse group and six (1.6%) in the low vertical group, P = .6. There were 28 (1.0%) symptomatic ruptures in the low transverse group and 3 (0.8%) in the low vertical group, P > .999. The study had a power of 80% to detect an increase in the low vertical rupture rate from 1% (as noted for low transverse incisions) to 3%.

CONCLUSION

Gravidas with a prior low vertical uterine incision are not at increased risk for uterine rupture during a trial of labor compared with women with a prior low transverse uterine incision.

Uterine rupture during induced or augmented labor in gravid women with one prior cesarean delivery

OBJECTIVE

Our purpose was to examine the risk of uterine rupture during induction or augmentation of labor in gravid women with 1 prior cesarean delivery.

STUDY DESIGN

The medical records of all gravid women with history of cesarean delivery who attempted a trial of labor during a 12-year period at a single center were reviewed. The current analysis was limited to women at term with 1 prior cesarean delivery and no other deliveries. The rate of uterine rupture in gravid women within that group undergoing induction was compared with that in spontaneously laboring women. The association of oxytocin induction, oxytocin augmentation, and use of prostaglandin E(2) gel with uterine rupture was determined. Logistic regression analysis was used to examine these associations, with control for confounding factors.

RESULTS

Of 2774 women in the analysis, 2214 had spontaneous onset of labor and 560 women had labor induced with oxytocin or prostaglandin E(2) gel. The overall rate of rupture among all patients with induction of labor was 2.3%, in comparison with 0.7% among women with spontaneous labor (P =.001). Among 1072 patients receiving oxytocin augmentation, the rate of uterine rupture was 1.0%, in comparison with 0.4% in nonaugmented, spontaneously laboring patients (P =.1). In a logistic regression model with control for birth weight, use of epidural, duration of labor, maternal age, year of delivery, and years since last birth, induction with oxytocin was associated with a 4.6-fold increased risk of uterine rupture compared with no oxytocin use (95% confidence interval, 1.5-14.1). In that model, augmentation with oxytocin was associated with an odds ratio of 2.3 (95% confidence interval, 0.8-7.0), and use of prostaglandin E(2) gel was associated with an odds ratio of 3.2 (95% confidence interval, 0.9-10.9). These differences were not statistically significant.

CONCLUSION

Induction of labor with oxytocin is associated with an increased rate of uterine rupture in gravid women with 1 prior uterine scar in comparison with the rate in spontaneously laboring women. Although the rate of uterine rupture was not statistically increased during oxytocin augmentation, use of oxytocin in such cases should proceed with caution.